U.S. patent application number 10/275541 was filed with the patent office on 2003-09-04 for wind power plant with a particle sensor.
Invention is credited to Wobben, Aloys.
Application Number | 20030165379 10/275541 |
Document ID | / |
Family ID | 7641030 |
Filed Date | 2003-09-04 |
United States Patent
Application |
20030165379 |
Kind Code |
A1 |
Wobben, Aloys |
September 4, 2003 |
Wind power plant with a particle sensor
Abstract
Wind power installations using more modern technology have long
been known. Such wind power installations have rotors comprising at
least one or more rotor blades. The rotors and accordingly the
rotor blades carried thereby of wind power installations are
subjected to a particular degree to the ambient environmental
influences such as for example rain, snow, hail or also insects. In
particular the leading edges of the rotor blades are heavily loaded
in that respect. In that situation it can happen that the rotor
blades and in particular the leading edges thereof, after some
time, suffer from (mechanical) damage, for which cost-intensive
repair is necessary, especially as a crane is frequently required
for that purpose and the entire wind power installation is also
stopped for a prolonged period due to the repair and under some
circumstances even individual rotor blades have to be transported
away to the repair location. The object of the present invention is
to reduce the erosion damage at the rotor blades and to avoid the
above-mentioned disadvantages. A method of operating a wind power
installation having at least one sensor for detecting the number
and/or the speed and/or the impulse of particles which impinge on
the sensor, with a data processing and control device for
processing the measurement data detected by the sensor, wherein the
rotary speed of the rotor of the wind power installation is reduced
(by means of the data processing/control device) and/or the wind
power installation is stopped if a particle measurement value
measured by the sensor is exceeded.
Inventors: |
Wobben, Aloys; (Aurich,
DE) |
Correspondence
Address: |
SEED INTELLECTUAL PROPERTY LAW GROUP PLLC
701 FIFTH AVE
SUITE 6300
SEATTLE
WA
98104-7092
US
|
Family ID: |
7641030 |
Appl. No.: |
10/275541 |
Filed: |
April 21, 2003 |
PCT Filed: |
March 2, 2001 |
PCT NO: |
PCT/EP01/02376 |
Current U.S.
Class: |
415/1 ;
415/17 |
Current CPC
Class: |
F03D 7/0276 20130101;
Y02E 10/72 20130101; F03D 80/00 20160501; F03D 17/00 20160501; F03D
7/0264 20130101; F05B 2270/30 20130101 |
Class at
Publication: |
415/1 ;
415/17 |
International
Class: |
F03D 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 6, 2000 |
DE |
100221297 |
Claims
1. A method of operating a wind power installation having at least
one sensor for detecting the number and/or the speed and/or the
impulse of particles which impinge on the sensor, with a data
processing and control device for processing the measurement data
detected by the sensor, wherein the rotary speed of the rotor of
the wind power installation is reduced (by means of the data
processing/control device) and/or the wind power installation is
stopped if a particle measurement value measured by the sensor is
exceeded.
2. A method according to claim 1 characterised in that the rotary
speed of the wind power installation is reduced and the wind power
installation is stopped if a given number of particles has been
measured by the sensor within a given period of time.
3. A method according to one of the preceding claims characterised
in that water drops (raindrops) and/or hailstones and/or grains of
dust are measured as particles.
4. A wind power installation for carrying out the method according
to one of the preceding claims comprising at least one sensor for
detecting the number, the energy and/or the impulse of particles
which impinge on the sensor, wherein the sensor is connected to a
data processing and control device which processes measurement data
ascertained by the sensor and reduces the rotary speed of the wind
power installation and optionally stops the wind power installation
when a predetermined particle measurement value is exceeded.
5. A wind power installation according to claim 4 characterised in
that the wind power installation has a plurality of sensors for
measuring particles.
6. A wind power installation according to one of claims 4 and 5
characterised in that the sensor or the plurality of sensors is or
are arranged at or on the rotor blades of the wind power
installation.
7. A wind power installation according to one of claims 4 to 6
characterised in that a sensor detects the number of impinging
particles (per time) and/or the impingement speed of particles
against the sensor and/or the impulse value of impinging
particles.
8. A wind power installation according to one of claims 4 to 7
characterised in that the sensor is arranged at the leading edge of
a rotor blade of the wind power installation.
9. A wind power installation according to claim 8 characterised in
that at least one sensor is arranged in the region of the rotor
blade tip or another region of the wind power installation, for
example the pod.
Description
[0001] Wind power installations using more modern technology have
long been known. Such wind power installations have rotors
comprising at least one or more rotor blades. The rotors and
accordingly the rotor blades carried thereby of wind power
installations are subjected to a particular degree to the ambient
environmental influences such as for example rain, snow, hail or
also insects. In particular the leading edges of the rotor blades
are heavily loaded in that respect. In that situation it can happen
that the rotor blades and in particular the leading edges thereof,
after some time, suffer from (mechanical) damage, for which
cost-intensive repair is necessary, especially as a crane is
frequently required for that purpose and the entire wind power
installation is also stopped for a prolonged period due to the
repair and under some circumstances even individual rotor blades
have to be transported away to the repair location.
[0002] Such damage is to be attributed to erosion effects which
damage the surface--the so-called gel coat--of the rotor blades,
which as the counterpart results in a worsening of the aerodynamic
properties of the blades.
[0003] The object of the present invention is to reduce the erosion
damage at the rotor blades and to avoid the above-mentioned
disadvantages.
[0004] In accordance with the invention that object is attained by
a method having the features of claim 1 and a wind power
installation for carrying out the method as set forth in claim 4.
Advantageous developments are described in the appendant
claims.
[0005] The strength of the influence of weather conditions such as
rain, snow, hail or also insects on the rotor blade leading edge is
substantially dependent on the rotary speed of the wind power
installation. The faster the blades are rotating, the
correspondingly higher is the speed of the rotor blade tip and the
correspondingly greater is the impingement speed of particles such
as for example raindrops, hailstones, snowflakes, insects or even
grains of dust--referred to hereinafter generally as
particles--against the rotor blade.
[0006] Wind power installations in accordance with the state of the
art are generally operated with given operating characteristics,
irrespective of the weather. In the case of installations with a
variable rotary speed--such as for example the wind power
installations from Enercon of type E-40 or E-66 et al--that
signifies for example a given installation-typical rotary
speed-power characteristic.
[0007] In the case of the wind power installations nowadays--of the
above-mentioned type--of the order of magnitude of between 500 kW
and 1.5 MW, the maximum blade tip speeds are in the range of 65-75
m/s or corresponding to 234-270 kph.
[0008] The invention is based on the realisation that the greatest
erosion damage is caused at the rotor blade leading edge by
particles which impact against the rotor blade leading edge.
[0009] In accordance with the invention it is now proposed that a
wind power installation be equipped with one or more sensors which
can detect the respective (wind-independent) weather conditions and
give corresponding signals to the wind power installation control
system which suitably reacts thereto by reducing the rotary speed
of the rotor of the installation for example in heavy rain--that is
to say with a high number of particles within a predetermined unit
of time (for example within a minute).
[0010] The method according to the invention and the wind power
installation according to the invention make it possible to avoid
or drastically reduce weather-induced erosion damage to the wind
power installation. That in turn results in a reduction in
expensive rotor blade repairs and in addition the fact of keeping
the surfaces of the rotor blades intact can afford a uniform level
of efficiency of the wind power installation. The invention is
described in greater detail hereinafter by means of an
embodiment.
[0011] The Figure is a diagrammatic view showing a wind power
installation 3 having a rotor 4 which comprises three rotor blades
5. Mounted on the rotor blade hub 4 and/or at the rotor blades 5
(the leading edge) are sensors 1, 2 which measure there the
incidence against the sensor of particles which are borne on the
wind to the wind power installation. The sensor or sensors are
connected to a data processing device 6 (PC) of the wind power
installation, which evaluates the measured data and sets for
example a suitable amount/time ratio, that is to say, detects the
number of particles over a given period of time. If more than a
predetermined number of particles, for example 10-20 particles
(raindrops) impinge on a sensor within a given unit of time, for
example 5-10 seconds, the rotary speed of the wind power
installation is reduced by means of a program stored in the data
processing device. That admittedly also results in a reduction in
the total power which the wind power installation produces. As
however the rainy times are usually relatively short in comparison
with the periods which are free from precipitation, that is
scarcely significant and it is possible to provide for effective
protection for the rotor blades if the rotary speed thereof is
reduced, for example halved, during the precipitation periods.
[0012] It will be appreciated that the data processing device also
processes as usual the measured wind data which are measured with
other sensors and causes a reduction in the rotary speed of the
rotor only when the wind speed exceeds a predetermined value.
[0013] It is also possible by means of the data processing device
to effect measurement of the particle amount, particle speed and/or
particle impulses (the so-called precipitation energy), that is to
say the precipitation power (amount of precipitation (particles),
speed of the precipitation) can be detected (integrated) over a
given period of time and the reduction in the rotary speed is
initiated when the precipitation energy or precipitation power
exceeds a predetermined value.
[0014] It is also possible by means of the sensors to measure an
addition or integration of the impulses (mass of a particle
multiplied by the impingement speed of the particle).
[0015] If the impulses caused by particles exceed a predetermined
value in respect of their magnitude, a reduction in rotary speed is
automatically effected so that this also automatically results in a
reduction in the impulse forces on the rotor blades, caused by the
precipitations.
* * * * *